Radiation and various devices that produce radiation are prevalent in today's highly technical world. Generally, radiation can be classified as one or more of neutron, X-ray, gamma ray, alpha particle, or beta particle and the term “radiation” is defined herein as containing at least one of these types. It will be appreciated that in many instances it is desirable to determine the specific type of radiation and may also be desirable to determine the strength and direction of the radiation.
In the prior art various apparatus is used to detect the various types of radiation. For example, current neutron detectors include either gas detectors or scintillators. A typical gas detector includes BF3 in a Geiger tube. A neutron incident on the Geiger tube causes a nuclear transmutation in the Boron that leads to the formation of a charged particle that is detected in the Geiger tube. Hence, the use of BF3 in the Geiger tube makes the device sensitive to neutrons.
A ‘scintillator’ is defined herein as a material that emits light when radiation passes through it. A phosphor is an example of a scintillator since it exhibits phosphorescence after becoming excited into a relatively long lived state and light emission occurs. Gadolinium and other rare earths are the key constituents of several phosphors. Some phosphors commercially available for use as X-ray screens, neutron detectors, alpha particle scintillators, etc. are:
Gd2O2S:Tb(P43), green (peak at 545 nm) 1.5 ms decay to 10%, low afterglow, high X-ray absorption, for X-ray, neutrons and gamma;
Gd2O2S:Eu, red (627 nm) 850 μs decay, afterglow, high X-ray absorption, for X-ray, neutrons and gamma;
Gd2O2S:Pr, green (513 nm), 7 μs decay, no afterglow, high X-ray absorption, for X-ray, neutrons and gamma;
Gd2O2S:Pr,Ce,F, green (513 nm), 4 μs decay, no afterglow, high X-ray absorption, for X-ray, neutrons and gamma;
Y2O2S:Tb(P45), white (545 nm), 1.5 ms decay, low afterglow, high X-ray absorption, for low energy X-ray;
Y2O2S:Eu(P22R), red (627 nm), 850 μs decay, afterglow, for low energy X-ray; and
Y2O2S:Pr, white (513 nm), 7 μs decay, afterglow, for low energy X-ray.
Many additional scintillator/phosphor materials are known and can be readily determined
Radiation detectors utilizing scintillator materials typically include a large piece of plastic or glass doped with neutron sensitive phosphor and placed in proximity to a multiplier tube. Thus, in response to a neutron impinging on the phosphor, light is emitted which is sensed by the multiplier tube. This entire apparatus is relatively large and unwieldy.
Traditional energy dispersive X-ray or gamma ray detectors, such as HPGe (high purity Germanium) gamma ray detectors or SiLi (Lithium drifter Silicon) X-ray detectors, are also available and presently in use. However, these devices are relatively expensive and, as understood in the art, difficult to produce in large numbers.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
An object of the present invention is to provide a new and improved radiation detector.
Another object of the present invention is to provide a radiation detector that is relatively small, easy to fabricate, and can be easily incorporated into other extensive testers, sensors, and/or detectors.
Another object of the present invention is to provide a new and improved method of fabricating radiation detectors.
Another object of the present invention is to provide a new and improved method of integrating radiation detectors into testing and sensing apparatus that is simpler and cheaper to fabricate and use.